Bioabsorbable casing for surgical sling assembly

ABSTRACT

The invention provides a surgical sling assembly for implanting in tissue to provide anatomical support in a patient The surgical sling assembly includes a sling and a biocompatible casing enclosing at least a portion of the sling. The biocompatible casing is absorbed by the patient&#39;s tissues after the surgical sling assembly is positioned within the patient&#39;s tissue to provide anatomical support.

TECHNICAL FIELD

The invention generally relates to surgical sling assemblies, andrelated methods, for providing anatomical support in a patient's body.More particularly, the invention relates to surgical sling assemblies,and related methods, that include bioabsorbable casings.

BACKGROUND INFORMATION

Stress urinary incontinence (SUI) affects primarily women and isgenerally caused by two conditions, intrinsic sphincter deficiency (ISD)and hypermobility. These conditions may occur independently or incombination. In ISD, the urinary sphincter valve, located within theurethra, fails to close properly (coapt), causing urine to leak out ofthe urethra during stressful activity. Hypermobility is a condition inwhich the pelvic floor is distended, weakened, or damaged, causing thebladder neck and proximal urethra to rotate and descend in response toincreases in intra-abdominal pressure (e.g., due to sneezing, coughing,straining, etc.). The result is that there is an insufficient responsetime to promote urethral closure and, consequently, urine leakage and/orflow results.

A popular treatment of SUI is the use of a surgical sling that is placedunder a patient's bladder neck or mid-urethra to provide a urethralplatform. Placement of the surgical sling limits the endopelvic fasciadrop while providing compression to the urethral sphincter to improvecoaptation. Typically, a protective sleeve encloses the sling during theplacement procedure. Once the surgical sling assembly, which includesthe sling and the sleeve, is correctly positioned in the patient'speriurethral tissues, the sleeve is physically removed from about thesling and withdrawn from the patient's body, leaving behind only thesling in the patient's tissues.

The current steps and procedures used to physically remove the sleevefrom about the sling which it encloses are, however, problematic. Forinstance, while physically removing the sleeve from about the sling,friction between the sleeve and the sling may cause the sling to bedragged away from its preferred position adjacent the mid-urethra, totwist, or to otherwise become misplaced. Ultimately, the utility of thesling is hampered and patient discomfort is increased.

Improved surgical sling assemblies, and related methods, for treatingSUI are, therefore, needed.

SUMMARY OF THE INVENTION

The present invention provides a surgical sling assembly, and relatedmethods, for providing anatomical support in a patient's body (e.g., asurgical sling assembly for treating urinary incontinence in a patient).The surgical sling assembly, and related methods, of the invention havethe advantage of obviating the need to physically remove a sleeve fromabout a sling.

In one aspect of the invention, a surgical sling assembly for implantingin tissue to provide anatomical support in a patient includes a slingand a biocompatible casing. The biocompatible casing encloses at least aportion of the sling and includes a bioabsorbable material. Thebiocompatible casing is absorbed by the patient's tissues after thesurgical sling assembly is positioned within the patient's tissue toprovide anatomical support. As the term is used herein, bioabsorbablemeans removal of a substance in a patient's tissue by physiologic orpathologic means.

In one embodiment of this aspect of the invention, the biocompatiblecasing includes a sleeve. Alternatively, the biocompatible casingincludes a coating. The bioabsorbable material may be an alginate, asugar based formulation, a starch, a gelatin, cellulose, polyvinylalcohol, polyglycolic acid, polylactic acid, polydioxinone, or alubricious material. In one embodiment, the surgical sling assembly ispositioned within a patient's periurethral tissues to treat urinaryincontinence. In one such embodiment, the biocompatible casing isabsorbed by the patient's tissues in less than ten minutes after thesurgical sling assembly is positioned within the patient's periurethraltissues. In one such particular embodiment, the biocompatible casing isabsorbed by the patient's tissues in eight to ten minutes after thesurgical sling assembly is positioned within the patient's periurethraltissues.

In another aspect, the invention relates to a method for providinganatomical support in a patient. The method includes providing asurgical sling assembly as described above and positioning the slingwithin the patient's tissues.

In one embodiment of this aspect of the invention, the sling ispositioned within a patient's periurethral tissues to treat urinaryincontinence.

The foregoing and other objects, aspects, features, and advantages ofthe invention will become more apparent from the following descriptionand from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention.

FIG. 1 depicts a top view of a sling assembly according to anillustrative embodiment of the invention.

FIG. 2 depicts a top view of a sling according to an illustrativeembodiment of the invention.

FIG. 3 depicts a top view of a sling assembly according to anotherillustrative embodiment of the invention.

FIG. 4 depicts a perspective view of a delivery system used to deliver asling assembly to the patient's periurethral tissues in accordance withan illustrative embodiment of the invention.

FIG. 5 depicts the placement of a sling assembly, including abioabsorbable casing, in a patient's periurethral tissues, according toan illustrative embodiment of the invention.

FIG. 6 depicts the placement of a sling in a patient's periurethraltissues, after the casing of FIG. 5 has been absorbed by the patient'stissues, according to an illustrative embodiment the invention.

DESCRIPTION

In general, the invention pertains to surgical sling assemblies, andrelated methods, for providing anatomical support in a patient's body(e.g., a surgical sling assembly for the treatment of urinaryincontinence). All of the embodiments have in common a sling at leastpartially enclosed within a bioabsorbable casing.

FIG. 1 depicts a surgical sling assembly 100 according to anillustrative embodiment of the invention. In the illustrativeembodiment, the surgical sling assembly 100 includes a sling 104 and acasing 108. The sling 104 is, for example, generally rectangular inshape and flat, or sheet-like. In a preferred embodiment, the sling 104is a mesh sling. In one embodiment, the sling 104 is knit from fibers,such as, for example, polymeric fibers. However, in alternativeembodiments, the sling 104 may be made of any suitable materials,including, for example, native mammalian tissue or any combination ofthe above materials. In the illustrative embodiment, the sling 104includes a mid-length portion 112, which has end points 116A, 116B, andtwo end-length portions 120A, 120B. The two end-length portions 120A,120B extend from the end points 116A, 116B of the mid-length portion 112to sling ends 124A, 124B, respectively. The two end-length portions120A, 120B are, in one embodiment, of substantially equal length, suchthat the mid-length portion 112 is generally centered along the longaxis of the sling 104. Alternatively, in another embodiment, the twoend-length portions 120A, 120B are of different lengths and themid-length portion 112 is eccentric (not shown).

FIG. 2 depicts a sling 104 according to an illustrative embodiment ofthe invention. In the illustrative embodiment, the end-length portions120A, 120B are tanged (i.e., rough) portions of the sling 104 that, asdescribed below, engage the patient's periurethral tissues and securethe sling 104 in position. For example, in one embodiment, fiber endsextend/project from the tanged end-length portions 120A, 120B. For itspart, the mid-length portion 112 is, in the illustrative embodiment, ade-tanged (i.e., a smooth) portion of the sling 104 that is preferablyplaced under the patient's mid-urethra. For example, in one embodiment,the de-tanged mid-length portion 112 is heat sealed to remove any sharpfiber ends and to ensure that its surfaces remain smooth.

The casing 108 encloses at least a portion of the sling 104. In oneembodiment, as illustrated in FIG. 1, the casing 108 encloses the entiresling 104. In another embodiment, the casing 108 encloses only thetanged end-length portions 120A, 120B of the sling 104. In yet anotherembodiment, the casing 108 encloses the tanged end-length portions 120A,120B and a portion of one or both sides of the de-tanged mid-lengthportion 112.

According to the illustrative embodiment shown in FIG. 1, the casing 108is a sleeve 128, e.g., a flattened tube. The sleeve 128 may include oneor more layers of the same or different materials that are laminatedtogether. In one embodiment, the sleeve 128 includes a first sleeve-end132A, a second sleeve-end 132B, and a lumen 136 extending from the firstsleeve-end 132A to the second sleeve-end 132B. Throughout the process ofdelivering the sling 104 to the patient's periurethral tissues, thesling 104 is located within the lumen 136 of the sleeve 128, between thefirst sleeve-end 132A and the second sleeve-end 132B, as illustrated. Assuch, the tanged end-length portions 120A, 120B of the sling 104 areprotected by the sleeve 128, thereby preventing the tanged end-lengthportions 120A, 120B from catching on the patient's tissues during thedelivery procedure. The casing 108 maintains the sling 104 in a flatconfiguration and prevents it from twisting, turning, or otherwisebecoming distorted, or even destroyed, during implantation of the sling104 in the patient's body.

FIG. 3 depicts a surgical sling assembly 100 according to anotherembodiment of the invention. As shown, the casing 108 is, in thisalternative embodiment, a coating 138. In one embodiment, the coating138 is applied to the sling 104 by, for example, dipping the sling 104in, or spraying the sling 104 with, a solution of a bioabsorbablematerial that later assumes the characteristics of a gel or solidifies.In another embodiment, the coating 138 is a polymer (e.g., athermoplastic) that is melted, freeze dried, or vacuum dried on to thesling 104. Alternatively, the coating 138 may be applied in a variety ofother manners. Moreover, more than one coating 138, of the same ordifferent materials, may be applied, in the same or different manners,to the sling 104. The coating 138 is of sufficient rigidity to preventthe tanged end-length portions 120A, 120B of the sling 104 from catchingon the patient's tissues during the delivery procedure.

In one embodiment, the casing 108 (e.g., the sleeve 128 or the coating138) is made of a biocompatible material. As used herein, the term“biocompatible” means a material that is non-toxic and that does notinduce inflammation or any other adverse reaction in the patient's bodythat would have a significantly adverse effect on the patient's health.

Moreover, in one embodiment, the casing 108 is made of a bioabsorbablematerial. Accordingly, as explained below, the casing 108 is absorbed bythe patient's tissues after the surgical sling assembly 100 ispositioned within the patient's periurethral tissues. Advantageously, anoperator (e.g., a physician) need not, therefore, remove the casing 108from about the sling 104 after the sling 104 is implanted in thepatient's tissues. Exemplary bioabsorbable materials from which thecasing 108 may be made include, but are not limited to, alginates, sugarbased formulations, starches, gelatins, cellulose, polyvinyl alcohol,polyglycolic acid (PGA), polylactic acid (PLA), polydioxinone (PDO), andother synthetic and natural polymers including combinations thereof. Inanother embodiment, the bioabsorbable material is a lubricious materialthat, during the delivery procedure, reduces the friction between thesling assembly 100 and the patient's periurethral tissues and therebyfacilitates placement of the sling assembly 100.

In another aspect, the invention provides a method for treating urinaryincontinence. FIG. 4 depicts an exemplary delivery system 148 that isused to deliver the sling assembly 100 to the patient's periurethraltissues in accordance with an illustrative embodiment of the invention.As shown, the delivery system 148 includes a delivery apparatus 152,connectors such as guide tubes 156A, 156B, and the sling assembly 100.In other embodiments, the guide tubes 156A, 156B may be replaced byother types of connectors (not shown). In one embodiment, each of theguide tubes 156A, 156B includes a proximal opening 160, a distal opening164, and a lumen 168 extending from the proximal opening 160 to thedistal opening 164. The exemplary delivery apparatus 152 includes ahandle 172 and a cannula 176. In one embodiment, a first end 180A of thesling assembly 100 is coupled to a proximal portion 182A of the firstguide tube 156A, and a second end 180B of the sling assembly 100 iscoupled to a proximal portion 182B of the second guide tube 156B.

In an exemplary method of treating urinary incontinence, the operatorloads the first guide tube 156A onto the cannula 176 illustrated in FIG.4. Specifically, with continued reference to FIG. 4, a distal end 184 ofthe cannula 176 is inserted through the proximal opening 160A of thefirst guide tube 156A. The distal end 184 of the cannula 176 is advancedthrough the lumen 168A of the first guide tube 156A until it exits fromthe distal opening 164A of the first guide tube 156A. Illustratively,the operator then introduces the distal end 184 of the cannula 176 intothe patient's tissues transvaginally at a first site until the distalend 184 of the cannula 176 emerges once again from the patient's tissuesat a second site, such as at the abdominal wall. The operator grasps andstabilizes a distal portion 186A of the first guide tube 156A thatemerges from the patient's tissues at the second site. While theoperator stabilizes the grasped portion of the first guide tube 156A,the cannula 176 is backed out of the patient's tissues, leaving behindthe first guide tube 156A in the patient's tissues. The operator thenloads a second guide tube 156B onto the cannula 176 of the deliveryapparatus 152 and repeats the above-described procedure on the oppositeside of the patient's periurethral tissue.

With both guide tubes 156A, 156B in place in the patient's tissues, theoperator performs a cystoscopy to confirm that the guide tubes 156A,156B have not penetrated the urinary bladder. Once so confirmed, theoperator grasps the distal portions 186A, 186B of the guide tubes 156A,156B, respectively, where they emerge from the patient's tissues at theabdominal wall and withdraws the guide tubes 156A, 156B. The operatorthen adjusts the position of the sling assembly 100 in the patient'speriurethral tissue.

Referring now to FIG. 5, an exemplary method of treating urinaryincontinence includes implanting the sling assembly 100, including thesling 104 and the casing 108, in a patient's periurethral tissues 140and positioning the sling assembly 100 adjacent the patient's urethra144. In one particular embodiment, an operator places the de-tangedmid-length portion 112 of the sling 104 adjacent the urethra 144.Referring again to FIG. 4, once the sling assembly 100 is correctlypositioned, the operator uncouples the ends 180A, 180B of the slingassembly 100 from the guide tubes 156A, 156B. The sling assembly 100,including the sling 104 and the casing 108, is left behind in thepatient's periurethral tissues 140, as illustrated in FIG. 5.

In alternative embodiments, rather than using a transvaginal approach asdescribed above, the operator approaches the patient's periurethraltissues 140 using a supra-pubic approach (i.e., percutaneously throughthe abdominal wall, abdominal fascia, and rectus fascia), atransobturator approach (i e., around the ischiopubic ramuspercutaneously through the obturator membrane and periurethralendopelvic fascia to a vaginal incision), or a pre-pubic approach (i.e.,from the abdominal wall along the anterior surface of the pubic bone).Other alternative operable methodologies for placing a sling 104 with acasing 108 according to the invention in a patient's body, to provideanatomical support, are also contemplated within the scope of theinvention.

Referring now to FIG. 6, after a pre-determined period of time, such as,for example, less than ten minutes after placement of the surgical slingassembly 100 in the patient's periurethral tissues 140, the casing 108is absorbed by the patient's tissues. Preferably, the casing 108 isabsorbed by the patient's tissues between eight to ten minutes afterplacement of the surgical sling assembly 100 in the patient'speriurethral tissues 140. However, in alternate embodiments, the casing108 is absorbed by the patient's tissues after any period of timefollowing placement of the surgical sling assembly 100 in the patient'speriurethral tissues 140. Only the sling 104 is left behind in thepatient's periurethral tissues 140. Because the operator need notphysically remove the casing 108 from about the sling 104 in order toimplant the sling 104, the sling 104 is not at risk of shifting,twisting, or of otherwise being misplaced, as would be the case if thecasing 108 was physically removed. Advantageously, the de-tangedmid-length portion 112 of the sling 104 remains adjacent the urethra144. Tissue compression and eventual tissue in-growth at the tangedend-length portions 120A, 120B permanently secure the sling 104 inposition. The sling 104 provides the requisite support to assist inmaintaining continence.

The sling assembly 100 described above may terminate in any suitableconfiguration or structure such as loops, apertures, male and femaleconnectors, guide tubes, and the like. Exemplary configurations andstructures are disclosed in U.S. patent application Ser. Nos.10/093,371, 10/093,398, 10/093,424, 10/093,450, 10/093,498, and10/094,352 filed in the United States Patent Office on Mar. 7, 2002,which are based on and claim priority to provisional patent applicationSer. No. 60/274,843 filed in the United States Patent Office on Mar. 9,2001 and provisional patent application Ser. No. 60/286,863 filed in theUnited States Patent Office on Apr. 26, 2001, provisional patentapplication Ser. No. 60/403,555 filed in the United States Patent Officeon Aug. 14, 2002, provisional patent application Ser. No. 60/418,827filed in the United States Patent Office on Oct. 15, 2002, provisionalpatent application Ser. No. 60/418,642 filed in the United States PatentOffice on Oct. 15, 2002, provisional patent application Ser. No.60/434,167 filed in the United States Patent Office on Dec. 17, 2002,U.S. patent application Ser. No. 10/325,125 filed in the United StatesPatent Office on Dec. 19, 2002, provisional patent application Ser. No.60/449,465 filed in the United States Patent Office on Feb. 24, 2003,and provisional patent application Ser. No. 60/465,722 filed in theUnited States Patent Office on Apr. 25, 2003, all the disclosures ofwhich are hereby incorporated herein by reference in their entirety.

Moreover, the sling assembly 100 of the invention may be employed withany suitable delivery system. Such delivery systems include, forexample, those delivery systems configured for supra-pubic, pre-pubic,transvaginal, or transobturator approaches. Without limitation, deliverysystems and methodologies that may be employed in combination with thesling assembly 100 of the invention can be found, for example, in U.S.patent application Ser. Nos. 10/093,371, 10/093,398, 10/093,424,10/093,450, 10/093,498, and 10/094,352 filed in the United States PatentOffice on Mar. 7, 2002, which are based on and claim priority toprovisional patent application Ser. No. 60/274,843 filed in the UnitedStates Patent Office on Mar. 9, 2001 and provisional patent applicationSer. No. 60/286,863 filed in the United States Patent Office on Apr. 26,2001, provisional patent application Ser. No. 60/403,555 filed in theUnited States Patent Office on Aug. 14, 2002, provisional patentapplication Ser. No. 60/418,827 filed in the United States Patent Officeon Oct. 15, 2002, provisional patent application Ser. No. 60/418,642filed in the United States Patent Office on Oct. 15, 2002, andprovisional patent application Ser. No. 60/434,167 filed in the UnitedStates Patent Office on Dec. 17, 2002, all the disclosures of which arehereby incorporated herein by reference in their entirety.

Additionally, the sling 104 of the invention may have any suitable sizeor shape configuration and may include any complimentary features.Without limitation, various applicable sling configurations aredisclosed in U.S. patent application Ser. No. 09/916,983 filed in theUnited States Patent Office on Jul. 27, 2001, U.S. patent applicationSer. No. 10/092,872 filed in the United States Patent Office on Mar. 7,2002, provisional patent application Ser. No. 60/388,109 filed in theUnited States Patent Office on Jun. 12, 2002, provisional patentapplication Ser. No. 60/403,555 filed in the United States Patent Officeon Aug. 14, 2002, provisional patent application Ser. No. 60/449,465filed in the United States Patent Office on Feb. 24, 2003, provisionalpatent application Ser. No. 60/465,722 filed in the United States PatentOffice on Apr. 25, 2003, and U.S. patent application Ser. No. 10/460,112filed in the United States Patent Office on Jun. 12, 2003, all thedisclosures of which are hereby incorporated herein by reference intheir entirety.

Variations, modifications, and other implementations of what isdescribed herein will occur to those of ordinary skill in the artwithout departing from the spirit and the scope of the invention. Theinvention is not to be defined only by the preceding illustrativedescription.

1. A surgical sling assembly for implanting in tissue to provideanatomical support in a patient, comprising: a sling; and abiocompatible casing enclosing at least a portion of the sling, thebiocompatible casing comprising a bioabsorbable material, wherein thebiocompatible casing is absorbed by the patient's tissues after thesurgical sling assembly is positioned within the patient's tissue toprovide anatomical support.
 2. The sling assembly of claim 1, whereinthe biocompatible casing comprises a sleeve.
 3. The sling assembly ofclaim 1, wherein the biocompatible casing comprises a coating.
 4. Thesling assembly of claim 1, wherein the bioabsorbable material comprisesan alginate.
 5. The sling assembly of claim 1, wherein the bioabsorbablematerial comprises a sugar based formulation.
 6. The sling assembly ofclaim 1, wherein the bioabsorbable material comprises a starch.
 7. Thesling assembly of claim 1, wherein the bioabsorbable material comprisesa gelatin.
 8. The sling assembly of claim 1, wherein the bioabsorbablematerial comprises cellulose.
 9. The sling assembly of claim 1, whereinthe bioabsorbable material comprises polyvinyl alcohol.
 10. The slingassembly of claim 1, wherein the bioabsorbable material comprisespolyglycolic acid.
 11. The sling assembly of claim 1, wherein thebioabsorbable material comprises polylactic acid.
 12. The sling assemblyof claim 1, wherein the bioabsorbable material comprises polydioxinone.13. The sling assembly of claim 1, wherein the bioabsorbable materialcomprises a lubricious material.
 14. The sling assembly of claim 1,wherein the surgical sling assembly is positioned within a patient'speriurethral tissues to treat urinary incontinence.
 15. The slingassembly of claim 14, wherein the biocompatible casing is absorbed bythe patient's tissues in less than ten minutes after the surgical slingassembly is positioned within the patient's periurethral tissues. 16.The sling assembly of claim 15, wherein the biocompatible casing isabsorbed by the patient's tissues in eight to ten minutes after thesurgical sling assembly is positioned within the patient's periurethraltissues.
 17. A method for providing anatomical support in a patient,comprising: providing a surgical sling assembly, comprising: a sling;and a biocompatible casing enclosing at least a portion of the sling,the biocompatible casing comprising a bioabsorbable material, whereinthe biocompatible casing is absorbed by the patient's tissues after thesurgical sling assembly is positioned within the patient's tissue toprovide anatomical support; and positioning the sling within thepatient's tissue.
 18. The method of claim 17, wherein positioning thesling comprises positioning the sling within a patient's periurethraltissues to treat urinary incontinence.